subquery

An SQL SELECT statement inside another select or action query. You can use a subquery as an expression in the field (column) cell in the design grid for a query or to define criteria (search conditions) for a field (column). The result set of the embedded SELECT statement becomes part of the search condition for the main query. For example, the following query uses a subquery to find all suppliers in Sweden and then uses the results in a WHERE clause to find all products with the selected suppliers:

WHERE supplier_id IN
   (SELECT supplier_id
   FROM supplier
   WHERE (country = 'Sweden'))